This invention relates generally to systems and methods for implanting ions of preselected chemical species into semiconductor wafers and, specifically, to positioning and scanning the semiconductor wafers relative to the ion beam. More specifically, this invention relates to three interrelated aspects of the technology of wafer handling in ion implantation systems capable of producing high beam currents, e.g., boron ion beams in excess of ten milliamperes and arsenic ion beam in excess of thirty-five milliamperes. The three aspects relate to wafer mounting or clamping on a heat sink, scanning wafers through the ion beam, and orienting wafers relative to the ion beam during scanning.